The invention relates to a power-assisted closing device for doors, flaps, folding tops or roofs of vehicles, in particular passenger cars, in accordance with the features of the preamble of patent claim 1.
DE 37 08 095 A1 discloses a power-assisted lock for doors, flaps, folding tops or roofs on vehicles, which has a pivotably mounted rotary latch which interacts with a fastening peg, it being possible for the rotary latch to be releasably locked by a detent pawl and furthermore for it to be able to be driven to effect an unlocking or locking procedure by a power-dispensing member.
Furthermore, a functional disk having at least one latching projection for the detent pawl in the unlocking position of the lock and a bevel for releasing the detent pawl from the latching position into the switching position is mounted pivotably next to the rotary latch. Moreover, the rotary latch is likewise provided in the opposite direction of rotation with a latching projection and a bevel each having the same function, and a hydraulic cylinder is coupled to the functional disk, the functional disk having a play-afflicted drive-type connection to the rotary latch. The rapidly advancing rotation of the rotary latch, which is caused by the fastening peg during the locking, unlocks the functional disk, the rapidly advancing rotation of the functional disk, which is caused by the return of the hydraulic cylinder or is manually triggered, unlocking the rotary latch during unlocking.
Although a design of this type has been proven with regard to good reliability, the complex form of the rotary latch and the detent pawl, but also of the functional disk with its associated bevels and slots in which the hydraulic cylinder engages, results in a costly construction. Moreover, during the installation of the power-assisted lock the position of the functional disk with the hydraulic cylinder coupled thereto has to be brought into a defined position with regard both to the detent pawl and also to the rotary latch so that the sloping surfaces of the functional disk can come into operative connection with the associated sloping surfaces of the detent pawl or of the rotary latch. This means that the outlay on installation is increased.
The invention is therefore based on the object of providing a power-assisted closing device which in addition to the required, utmost reliability is also distinguished by a simple construction and ease of installation. The aim with this power-assisted closing device is to open and close the doors, flaps, folding tops or roofs of vehicles in a power-assisted manner or else automatically.
According to the invention, provision is made for a respective stop element to be pivotably mounted on the rotary latch and on the detent pawl, the stop elements interacting with the disk cam, which is driven by an actuating drive, in the opening procedure (in other words: unlocking procedure) or in the closing procedure (in other words: locking procedure). That means that in the unlocking procedure the stop element on the detent pawl is effective for opening (unlocking) the rotary latch, while the stop element on the rotary latch is ineffective and hence pivoted away in this case. On the other hand, in the locking procedure it is such that the stop element which is arranged on the rotary latch is effective so that by the latter the actuating drive can drive the rotary latch and lock the closing device. In this case, the stop element which is arranged on the detent pawl is ineffective. This arrangement ensures that the pivotable stop elements can be installed on the rotary latch and on the detent pawl, the detent pawl and the rotary latch being rotably mounted in a housing of the closing device. The assignment of the rotary disk cam to the detent pawl and the rotary latch results in installation being easy and rapid without attention having to be paid during the installation as to the position in which the disk cam has to be aligned with regard to the detent pawl or the rotary latch.
In a development of the invention, a restoring spring is assigned to a respective stop element. This ensures in a simple manner that the respectively appropriate stop element is effective or ineffective in the unlocking procedure or in the locking procedure. In the ineffective case, the stop element is rendered ineffective by the force of the restoring spring being overcome. In the effective case, the stop element bears by means of a form fit against the relevant counter part (rotary latch or detent pawl), with the result that the actuating drive can act via the disk cam on this counter part for unlocking or locking.
In a development of the invention, the disk cam has a peg which acts on the stop elements. The installation is further improved by this refinement, in particular by a peg protruding perpendicularly from the surface of the disk cam, a further advantage which can be mentioned being the flat construction. Installation is therefore made easy since the disk cam is pushed, for example, onto a peg of a housing half shell and further pegs are provided on the housing half shell to receive the detent pawl and the rotary latch. In the process, attention does not have to be paid to a certain position when fitting the elements and so malfunctions caused by erroneously installed elements are also avoided during initial operation.
In a development of the invention, the rotary latch can be driven in a geared-down manner by the actuating drive, this being required in order to overcome the forces when shutting the door (for example, triggered by the weight of the door or else the sealing forces).
In a development of the invention, the actuating drive is an electric motor which drives the disk cam in a geared-down manner. The advantageous result of this is a compact constructional unit.
In a development of the invention, for the locking procedure the actuating drive acts via the disk cam on the stop element of the rotary latch and for the unlocking procedure on the stop element of the detent pawl. That is to say that depending on the type of procedure only the one stop element is subjected to force and thus a function which is required for this desired procedure is triggered. In addition, it is thereby ensured that also only the desired procedure is triggered when the actuating drive is activated. Thus, for example in the locking procedure, i.e. when the rotary latch is being rotated and thus when the door is being shut, the detent pawl cannot be operated since if this was operated it would result in the locking procedure being terminated or prevented. The same happens in the unlocking procedure so that it is ensured that when, the detent pawl is driven to the effect of providing opening assistance, the door cannot be shut again onto the rotary latch by being subjected to force. This is thus a very important safety aspect.
In a development of the invention, the rotary latch has a preliminary catch which interacts with the detent pawl and a main catch, means being provided which detect at least the preliminary catch position of the rotary latch. This ensures that an operator brings the door, the rear flap or the trunk lid, for example, from the opened position into the so called preliminary catch position, the fastening peg, which is arranged on the door, the rear flap or the trunk lid, being intercepted by the rotary latch and held in a preliminary closing position. It should further be noted here that the fastening peg can also be arranged on a vehicle part which is secured to the body and the power-assisted closing device with the rotary latch, detent pawl, disk cam and actuating drive can be arranged in the door or the like.
As soon as the door or the like is brought into the preliminary closing position, this is recognized by the means and the actuating drive for the locking procedure (shutting assistance) is activated. As an alternative to the means which detect the preliminary catch position of the rotary latch, means can also be provided which detect the preliminary closing position of the door or the like per se. In a development of the invention, the means comprise a preliminary catch switch which can be operated by the rotary latch or the stop element thereof and optionally a main-catch switch which can be operated by the detent pawl. Means for detecting the position and on which the activation of the actuating drive depends can thereby be integrated in the immediate vicinity of the elements of the closing device, in particular can be integrated therewith in a housing. The outlay on cabling is thus also reduced as long as these switches (or other means in general) are accommodated in the housing together with the actuating drive and a control device which has yet to be described.
In a development of the invention, the actuating drive, in particular of the electric motor, can be operated in block mode. That means that the actuating drive is activated and drives the disk cam until the latter runs, in particular with its peg, onto the stop element which acts in a positively locking manner with the rotary latch or with the detent pawl, specifically in a manner such that further driving of the disk cam is no longer possible. This can be evaluated in a suitable manner (for example, by evaluating the increase in power of the actuating drive) and the actuating drive can be switched off as a result. Means for positional control (for example, microswitches, restoring springs or other means) can thus be dispensed with, as a result of which the installation is again simplified and the number of elements reduced.
In a development of the invention, the pivotably mounted detent pawl is subjected to force in the direction of the rotary latch, it thereby being ensured that after the detent pawl has been pivoted by the disk cam out of the operative range of the rotary latch, the detent pawl itself can again enter into operative connection with the rotary latch (for locking).